The present invention relates to the field of variable-lift devices using a gas that is lighter than air for rising in the atmosphere. More precisely, the invention relates to variable-lift devices provided with a tank for storing the lighter-than-air gas under pressure, such as helium, neon, methane, ethane, or hydrogen.
A variable-lift device can be used for moving or lifting heavy objects or objects of sizes that are too bulky for them to be transported by truck, train, or airplane.
In general, variable-lift devices are constituted by a balloon containing helium and a gondola attached to the balloon. The gondola contains various accessories needed for navigation. The balloon is constituted by a flexible envelope supported by a rigid structure. The rigid structure consists of an assembly of beams, a beam being an element that is long in one dimension relative to the other two dimensions. The shape the rigid structure gives to the flexible envelope is selected so as to be aerodynamic.
In the prior art, the gondola attached to the balloon contains the helium tanks, together with other accessories. The shape of the helium tank is selected so as to store a large quantity of helium while reducing the size and the weight of the tanks.
The present invention proposes making use of hollow beams to constitute at least a portion of the rigid structure which supports the flexible envelope constituting the balloon, and to store helium under pressure inside the hollow beams.
The present invention provides a variable-lift device using a gas that is lighter than air, the device comprising an outer envelope supported by a more rigid structure, the device being characterized in that said structure comprises a hollow beam having internal volume that is used as a tank for storing said gas. The hollow beam may be covered in a cloth that is leakproof relative to said gas and that thermally insulates the internal volume of the hollow beam. The hollow beam may be a hollow torus. The hollow torus may comprise at least two torus portions assembled together.
In a first variant of the invention, the structure of the device comprises at least two hollow toruses whose internal volumes are in communication. In a second variant of the invention, the structure of the device comprise at least two hollow toruses whose inside volumes are not in communication.
The present invention provides a saving in weight and reduces the space occupied in the gondola since the helium tank and the rigid structure are one and the same element.